This invention relates to an offshore storage facility and more particularly relates to a semisubmersible combined loading, mooring and storage facility for handling petroleum products and offshore locations.
A major consideration in the production of petroleum products from offshore deposits is the handling and transportation of such products once they have been produced. If feasible, it is usually desirable to lay submerged pipelines from the production site to short so that flow of products may be continuous regardless of weather or other adverse conditions. However, in many areas of the world where offshore production exists, the laying of submerged pipelines is infeasible due to a variety of reasons, e.g., distance to shore, uneveness of the marine bottom, etc. In such areas, other means must be provided to handle the products so that production may continue without prolonged interruptions.
In most instances where pipelines are unavailable, the petroleum products are accumulated in storage facilities near the production site and then loaded onto tankers for transportation to shore. The storage facilities which have been proposed for such use are of many basic types: (1) storage tanks which are affixed to and form an integral part of a production platform; (2) completely submerged storage tanks which rest directly on the marine bottom; (3) floating storage tanks such as surplus tankers, etc.; and (4) semisubmersible storage tanks which have a lower submerged section and an upper section affixed thereto which normally extends above the waterline when in an operable position. The present invention is directed to this latter type of storage facility.